The gutter system of a swimming pool is one of its most important components, and its design is determinative of many of the characteristics of the pool. However, what constitutes good gutter design has long been a perplexing problem in much dispute. What is recognized is that a swimming pool gutter system must provide an adequate surge flow capacity, especially when the pool is filled with swimmers, and it should not flood when a large group of swimmers enters the pool all at once. It should also provide a good surge- and wave- quelling capacity. Its ability to cope with surges and waves produced by swimmers is quite important to the competitive qualities of the swimming pool.
A problem related to gutter design is the removal of surface dirt. Some types of gutter are designed to provide a skimming action, but it has generally been conceded that the most efficient type of skimming action is provided by the scum gutter type of pool, and on all pools over 1,600 square feet in area, scum gutters are provided as a matter of course. In fact, in some states, surface skimmers are not permitted.
One type of swimming pool with a perimeter gutter provides for flow of water over the top of the gutter wall into the gutter trough at all times. Such a gutter system is described in U.S. Pat. No. 2,932,397 to Ogden dated Apr. 12, 1960. Another and older design appears in U.S. Pat. No. 1,797,397 to Booraem dated Mar. 24, 1931. Such a gutter provides a most efficient skimming action under normal flow conditions, but as soon as swimmers enter the pool, or a heavy surge or wave action is encountered, the additional flow of water over the top of the gutter tends to flood the gutter, after which skimming action is lost until the water can be drained away, and in fact some of the dirt already is the gutter may be washed back.
In an attempt to alleviate such a condition, a modification of the Ogden gutter has been proposed in U.S. Pat. No. 3,363,767 to Ellis dated Jan. 16, 1968, incorporating a plurality of skimmer opening spaced around the gutter at a lower level than the top of the gutter. In this system, when the pool is not in use, the skimmer weir is opened and skimming is obtained via the openings into the gutter (column 2, lines 19 to 24). When the pool is in use, the skimmer weirs are closed (column 2, lines 12 to 13), but the water level is held down below the lip of the gutter, providing a certain in-pool surge capacity, and avoiding a flooded gutter condition at the time of flow surges. However, when the pool is in heavy use and there is considerable wave or surge action over the top of the gutter, surface contaminants washed into the gutter may still be washed back into the pool.
U.S. Pat. Nos. 3,668,712 and 3,668,714, patented Jun. 13, 1972 to Baker, provide perimeter skimming gutters for swimming pools which can permit an adequate skimming action at all times, and provide an adequate surge capacity when the pool is in use, without the possibility of the gutter's flooding or dirt in the gutter's being washed back into the pool.
This is accomplished in U.S. Pat. No. 3,668,712 by combining a plurality of narrow, elongated, substantially horizontally disposed openings which are open at all times in a retaining wall disposed about the perimeter of the swimming pool, with the peripheral gutter conduit arranged to receive water spilling over the top of the retaining wall when the flow capacity of the elongated openings is exceeded. The elongated openings can be arranged to feed water into the main gutter conduit, or into a separate second gutter conduit, so as to keep these two water flows completely separate, and retain the dirt skimmed off the top of the pool in a separate place, to avoid the hazard of this dirt's being washed back into the pool, in the unlikely event of the first gutter conduit's being flooded during wave actions or surges. In this gutter system, the water level in the pool is normally maintained at the level of the skimmer openings in the gutter.
In U.S. Pat. No. 3,668,714, the perimeter skimming gutter comprises a first gutter conduit for disposition about the perimeter of a swimming pool, and adapted to carry water at a level below a predetermined level of water in the swimming pool; a retaining wall on the pool-side of the first gutter conduit, over the top of which wall water may flow from the pool into the first gutter conduit; and a second gutter conduit in fluid flow connection with the first, such fluid flow connection entering the first gutter conduit at a level below the top of the retaining wall, and adapted to drain off water from the first gutter conduit at any level exceeding a predetermined maximum level therein, so as to inhibit the level of water in the first gutter conduit from reaching the top of the retaining wall.
U.S. Pat. No. 3,668,713, patented Jun. 13, 1972 to Baker, provides a fluid flow and/or fluid pressure responsive gate weir for swimming pools, comprising in combination, a weir support; a fluid flow passage in the support; a gate member pivotably mounted in the support across the passage between flow-open and flow-closed positions; a gate control means disposed to encounter a fluid flow through and/or fluid pressure in the passage above a predetermined minimum, and responsive to such flow and/or pressure to pivot the gate member from a flow-open towards a flow-closed position; and means arranged to retain the gate member in the flow-open position under normal conditions of fluid flow and/or fluid pressure through the weir passage and to permit pivotal movement of the gate members towards a flow-closed position while such excessive fluid flow and/or fluid pressure continues.
Means can also be provided to return the gate member to the flow-open position when such excessive flow and/or pressure subsides, and/or returns to normal.
U.S. Pat. No. 3,815,160, dated Jun. 11, 1974 to Baker, provides a nonflooding perimeter skimming gutter wall for swimming pools, including a first gutter conduit for disposition about the perimeter of a swimming pool, and adapted to carry water at a level below a predetermined level of water in the swimming pool, a retaining wall on the pool-side of the first gutter conduit over the top of which wall a skimming flow of water may run from the pool into the first gutter conduit, a second gutter conduit within a peripheral wall below the first gutter conduit and adapted to carry water at a level above a predetermined level of water in the first gutter conduit, and a fluid flow connection between the two gutter conduits at such level and below the top of the retaining wall allowing water to flow from the first gutter conduit into the second gutter conduit whenever the water level on the first gutter conduit reaches the fluid flow connection, thereby inhibiting filling of the first gutter conduit appreciably above such level.
In the twin gutter structures provided in these patents, the two gutters are separate, and of fixed dimensions. While the gutters can be interconnected at a number of locations, flow therebetween is normally not possible until one or the other reaches a predetermined overflow level. This is highly desirable in most circumstances, but on occasion a single gutter of large capacity may be preferred. In a fixed-in-place structure of the type described, this is not possible to achieve.
In accordance with U.S. Pat. No. 4,050,104 patented Sep. 27, 1977 to Baker, a twin gutter system is provided in which the twin gutters can be kept separate or combined in one, as desired, by forming the two gutters with at least one common wall, of which at least a portion thereof can be removed. This feature can be applied in any of the twin gutter systems of U.S. Pat. Nos. 3,688,712, 3,668,713, 3,668,714, and 3,815,160 with or without a skimming function, as desired. The common wall can be all or part of a side wall, and end wall, a bottom wall, or a corner wall, of the gutters, as is illustrated in the drawings, which show preferred structural embodiments.
Thus, a perimeter gutter for swimming pools is provided comprising, in combination, first and second gutter conduits for disposition about the perimeter of a swimming pool, which conduits at least one is adapted to carry water at a level below a predetermined level of water in the swimming pool; a retaining wall on the pool-side of the gutter conduits, over the top of which wall water may flow from the pool into one of the gutter conduits; the first and second gutter conduits having at least one common wall therebetween, separating interior space of the second gutter conduit from interior space of the first gutter conduit, of which common wall at least a portion is removable, so that upon removal of the wall, said interior spaces are combined and form a gutter whose interior space is greater than the interior space of either gutter conduit.
The first and second gutter conduits can be in fluid flow communication either with the swimming pool or with each other, or with both.
The perimeter gutter structures of all of these patents is rather complex, and not susceptible of manufacture except at a highly sophisticated manufacturing facility. The gutters are best made as a plurality of units that are welded together on-site according to the pool size and shape required. The large number of exterior and interior walls that have to be welded together in leak-tight seals is formidable, and where these walls come together adjacent multiple joints are required that have to be introduced one at a time, which poses a formidable problem upon introduction of the second weld, so as to avoid opening up of the first weld in the process, besides taking considerable labor time on the part of highly skilled welders. This welding problem is especially severe in assembling the retaining wall, which usually requires installing several modular wall units, one on top of the other, in perfect alignment vertically and horizontally, from one modular unit to the next.
U.S. Pat. No. 4,758,292, patented Jul. 19, 1988 to Baker, provides a simplified pool-side retaining wall structure in which at the junction of three sheets, the walls can all be welded together simultaneously in one weld. The finished retaining wall comprises two conduits in alignment vertically, horizontally, or at any angle thereto, separated by and welded to a common divider wall, in single welds at each end of the divider wall. One side of the retaining wall forms a side retaining wall of the pool, and the other side forms the side wall of a gutter trough.
The modular bonded perimeter skimming gutter retaining wall for swimming pools according to that invention thus is especially designed for construction by simple bonding together of a plurality of modular units on-site, disposed about the perimeter of a swimming pool, as the retaining wall of the swimming pool, defining a pool-side wall of an open gutter conduit adapted to carry water at a level below a predetermined level of water in the swimming pool, over the top of which wall water may flow from the pool into the gutter, the retaining wall comprising two generally U-shaped channels open along one side and having open interiors defined by side walls extending from a common base, the channels being arranged with the open sides facing one another and bonded together along the end faces of the side walls to a common divider plate closing off each channel and the interior spaces thereof, thereby forming separated conduits of each channel, one of said conduits being adapted to carry clean water feed to the pool and the other of said conduits being adapted to carry water away from the pool.
The retaining wall is adapted for combination with a pool-side concrete or other built-in gutter structure at the perimeter of a swimming pool, or with a sheet of material shaped to form and complete the perimeter gutter structure and, in addition, if desired, the top coping of the swimming pool, so as to form a perimeter skimming gutter.